The present invention relates to in-mold labeling and in particular to label transferring devices for blow molding machines having separable molds.
Blow molding machines are well known in the art and have various designs, many of which employ a pair of moving platens on which are mounted a pair of separable mold sections which define the mold cavity. In such blow molding machines, the molding material is extruded or otherwise formed, the mold sections being separated by the platens in order to encircle the molding material parison. The mold sections are then brought together by the movable platens and the parison, typically after the platens and the closed mold sections carried thereby have been moved to a so-called calibration station, is blown to form the desired object, such as a container or the like.
It is desirable, particularly where the articles being blow molded are soap containers or the like, to thermoplastically adhere the labels to the containers during the blow molding process. This involves placing a preprinted label within one or both of the mold sections prior to the closing of the sections about the parison and the subsequent blowing procedure. Labels so adhered to the containers, as will be readily appreciated by those skilled in the art, have distinct advantages over post-molding applied labels. First and foremost, of course, in-mold labeling avoids the necessity of conducting a subsequent labeling process. Second, and nearly equally important, in-mold applied labels are much more resistant to abrasion such as is incurred in filling operations, shipment and the like. In-mold applied labels in general make for a more attractive packaging of the particular product.
In-mold labeling is not, however, without disadvantages. In the platen-type machines described heretofore, the time required to place the label within the mold after the previously molded container has been ejected reduces significantly the output of a given machine. In this inventor's co-pending application, entitled Blow Molding Label Transferring Device, Ser. No. 515,033, filed on even date herewith, the disclosure of which is hereby incorporated by reference, a system is disclosed and claimed which has the potential of reducing this time lapse. The instant invention, while perhaps more complicated from a mechanical standpoint, reduces this time lapse to virtually zero, permitting the platen-type machine to incorporate the in-mold labeling concept with virtually no loss in production capacity.